Description and Performance of Three Trailblazer II Reentry Research Vehicles

A description of the Trailblazer II reentry physics research vehicle capable of reentering a 40-pound payload into the atmosphere at 20,000 ft/sec is presented together with the description and results of three flight tests. The vehicle proved to be a workable system during flight tests by accomplishing the objective of reentering a prescribed payload. The dispersion of the impact points of the various stages was within the expected limits except that the first-stage impact was much closer to the launch point than was originally expected. Approximate wobble motions of the spinning body at various times were determined from telemetered quantities. It was possible to determine the chamber pressure time history of the third-stage rocket motor and the thrust time history of the fourth-stage rocket motor from the telemetry carried on- board some of the vehicles. The thrust and pressure curves indicated that the thrust was lower during the first part of the thrust period and higher during the latter part of the thrust period than the values expected for a nonspinning motor.